Manhole.



No. 726,823. PATBNTEDAPRLZB}1903'."

F. T. MOORE.

MANHOLE. APPLIOATION FILED MAY 20,1902

no MODEL.

SATES FREDERICK T. MOORE, OF WVILLIAM SPORT, PENNSYLVANIA, ASSIGNOR TO E. KEELER CO OF WILLIAMSPORT, PENNSYLVANIA.

MAN

HOLE.

SPECIFICATION forming part of Letters Patent No. 726,823, dated April 28, 1903. l

Application filed May 20, 1902. Serial No. 108,229. (No model.)

To aZZ whom it. may concern:

Be itknown that I, FREDERICK T. MOORE, a citizen of the United States, residing at Williamsport, in the county of Lycoming and State of Pennsylvania, have invented a new and useful Improvement in Manholes for Boilers, &c., of which the following is a specification.

This invention relates to certain improvements in theconstruction of manholes of that class in which the wall of the manhole is in the form of an inwardly-extending flange, the inner edge or face of which is adapted for the 1 reception of a gasket pressed into position by :5 the manhole-cover. p

In the manufacture of boiler-heads and plates where manholes are to be formed it is usual to form an inwardlyextending flange by the ordinary flanging-machine or by die stamping or hammering, the edge of the flange serving for the reception of a specially-formed and expensive gasket and manhole-cover.

The present invention is designed principally for the formation of a reinforced flange having a wide bearing-surface for the gasket,

so that rubber or any other kind of gasket.

in ordinary use may be employed without resorting to specially-prepared manhole-plates or gaskets.

In the drawings, Figure 1 is a perspective view illustrating the preliminary steps of forming an internally-flanged manhole. Fig.

2 is a similar view showing the application of an auxiliary reinforcing-ring to the outer 3 5 wall of the flange. Fig.3 represents the finished manhole. Figs. 4 and 5 are enlarged sectional views through one wall of the manhole, as illustrated in Figs. 2 and 3, respectively.

Similar numerals of reference are employed to indicate corresponding parts throughout the several figures of the drawings.

In carrying the invention into eifect a suit ably-shaped opening of smaller diameter than the manhole to be made is formed in a plate of metal representing thehead or other desired portion of the boiler or tank in which the manhole is to be situated. The metal around the wall of the opening is then bent 5o inwardly by a flanging-machine or other suitable apparatus to form' an inwardly-extending flange the internal diameter of which governs the size of the manhole. The inner edge of the flange is generally rough and uneven, owing in someinstances to the character of the tools employed in cutting the opening and in others to the process followed in forming the flange, and in some cases the metal will be thinner at some points than at others.

On the outer wall of the flange 2 is placed -a reinforcing-ring 3 of any suitable dimensions, the ring being preferably shrunken for the purpose of forming a comparatively tight joint without the employment of auxiliary fastening devices. The inner surface of the ring is preferably placed a slight distance below the uneven edge of the flange, as indicated in Figs. 2 and 42 The flanged plate is then placed on a planer, milling-machine, or other suitable tool, and both the edge of the are faced off to form a smooth flat surface for contact with the gasket.

Inthe formationof manholes, as usually practiced, by hydraulic presses or by the usual 'roller flanging-machine there is always danger of the metal of the flange being of different thickness at different-points, and this has a weakening tendency, which is corrected by the application of the ring of bar-iron, the latter also forming an extensive surface for contact with the gasket and permitting the use of an ordinary form of rubber or other gasket and the use ofan ordinary plate-cover, rendering it unnecessary to employ a specially-prepared manhole-cover and the expensive form of gasketordinarily employed.

I am aware that it hasheretofore been proposed to strengthen a manhole-flangeby the employment of a plate of metalstamped up with the flange; but such a construction adds but little to the strength or usefulness of the device, owing to the fact that the thickness of the auxiliary plate is limited not. only by the strength of the flanging-machine, but also by the strength of the boiler-shell, it being impossible to employ an auxiliary plate of excessive thickness, owing to the danger of rupturing the boiler-shell during the flanging process. In a manhole made in this manner, moreover, the flanging operation in many flange and the adjacent surface of the ring cases results in the formation of a flange of varying thickness and the production of an uneven and irregular gasket-receiving surface, while in a manhole formed in accordance with my invention the ring of bar-iron may be of any desired cross-sectional area to correct any irregularities in the thickness of the flange, and the gasket-receiving surface may be of any Width.

Having thus described the invention, what is claimed is- As a new article of manufacture, a boilerhead having an internally-flanged manhole of which the flange or wall is formed by inturning the metal of the head, and a reinforcing-ring of bar-iron of considerably greater area than the flange and secured to the outer wall of said flange, the edge of the flange and the corresponding face of the ring being faced. In testimony that I claim the foregoing as my own I have hereto aifixed my signature in the presence of two witnesses.

FREDERICK T. MOORE. Witnesses: a,

W. W. GRAY, THOMAS MARTIN. 

